1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3
4 #include <test_progs.h>
5 #include <sys/stat.h>
6
7 #include "test_link_pinning.skel.h"
8
9 static int duration = 0;
10
test_link_pinning_subtest(struct bpf_program * prog,struct test_link_pinning__bss * bss)11 void test_link_pinning_subtest(struct bpf_program *prog,
12 struct test_link_pinning__bss *bss)
13 {
14 const char *link_pin_path = "/sys/fs/bpf/pinned_link_test";
15 struct stat statbuf = {};
16 struct bpf_link *link;
17 int err, i;
18
19 link = bpf_program__attach(prog);
20 if (CHECK(IS_ERR(link), "link_attach", "err: %ld\n", PTR_ERR(link)))
21 goto cleanup;
22
23 bss->in = 1;
24 usleep(1);
25 CHECK(bss->out != 1, "res_check1", "exp %d, got %d\n", 1, bss->out);
26
27 /* pin link */
28 err = bpf_link__pin(link, link_pin_path);
29 if (CHECK(err, "link_pin", "err: %d\n", err))
30 goto cleanup;
31
32 CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path1",
33 "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link));
34
35 /* check that link was pinned */
36 err = stat(link_pin_path, &statbuf);
37 if (CHECK(err, "stat_link", "err %d errno %d\n", err, errno))
38 goto cleanup;
39
40 bss->in = 2;
41 usleep(1);
42 CHECK(bss->out != 2, "res_check2", "exp %d, got %d\n", 2, bss->out);
43
44 /* destroy link, pinned link should keep program attached */
45 bpf_link__destroy(link);
46 link = NULL;
47
48 bss->in = 3;
49 usleep(1);
50 CHECK(bss->out != 3, "res_check3", "exp %d, got %d\n", 3, bss->out);
51
52 /* re-open link from BPFFS */
53 link = bpf_link__open(link_pin_path);
54 if (CHECK(IS_ERR(link), "link_open", "err: %ld\n", PTR_ERR(link)))
55 goto cleanup;
56
57 CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path2",
58 "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link));
59
60 /* unpin link from BPFFS, program still attached */
61 err = bpf_link__unpin(link);
62 if (CHECK(err, "link_unpin", "err: %d\n", err))
63 goto cleanup;
64
65 /* still active, as we have FD open now */
66 bss->in = 4;
67 usleep(1);
68 CHECK(bss->out != 4, "res_check4", "exp %d, got %d\n", 4, bss->out);
69
70 bpf_link__destroy(link);
71 link = NULL;
72
73 /* Validate it's finally detached.
74 * Actual detachment might get delayed a bit, so there is no reliable
75 * way to validate it immediately here, let's count up for long enough
76 * and see if eventually output stops being updated
77 */
78 for (i = 5; i < 10000; i++) {
79 bss->in = i;
80 usleep(1);
81 if (bss->out == i - 1)
82 break;
83 }
84 CHECK(i == 10000, "link_attached", "got to iteration #%d\n", i);
85
86 cleanup:
87 if (!IS_ERR(link))
88 bpf_link__destroy(link);
89 }
90
test_link_pinning(void)91 void test_link_pinning(void)
92 {
93 struct test_link_pinning* skel;
94
95 skel = test_link_pinning__open_and_load();
96 if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
97 return;
98
99 if (test__start_subtest("pin_raw_tp"))
100 test_link_pinning_subtest(skel->progs.raw_tp_prog, skel->bss);
101 if (test__start_subtest("pin_tp_btf"))
102 test_link_pinning_subtest(skel->progs.tp_btf_prog, skel->bss);
103
104 test_link_pinning__destroy(skel);
105 }
106